993521 has 4 divisors (see below), whose sum is σ = 1001472. Its totient is φ = 985572.

The previous prime is 993493. The next prime is 993527. The reversal of 993521 is 125399.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-993521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 993521.

It is not an unprimeable number, because it can be changed into a prime (993527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3785 + ... + 4038.

It is an arithmetic number, because the mean of its divisors is an integer number (250368).

2⁹⁹³⁵²¹ is an apocalyptic number.

It is an amenable number.

993521 is a deficient number, since it is larger than the sum of its proper divisors (7951).

993521 is a wasteful number, since it uses less digits than its factorization.

993521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7950.

The product of its digits is 2430, while the sum is 29.

The square root of 993521 is about 996.7552357525. The cubic root of 993521 is about 99.7835652312.

The spelling of 993521 in words is "nine hundred ninety-three thousand, five hundred twenty-one".